Answer: 20
Step-by-step explanation:
If you would like to solve the system of equations, you can do this using the following steps:
5p - 3r = 1 /*2
8p + 6r = 4
__________
10p - 6r = 2
<span>8p + 6r = 4
</span>__________
10p - 6r + 8p + 6r = 2 + 4
18p = 6
p = 6/18
p = 1/3
<span>5p - 3r = 1
</span>5 * 1/3 - 3r = 1
5/3 - 3r = 1
5/3 - 1 = 3r
5/3 - 3/3 = 3r
2/3 = 3r
r = 2/9
(p, r) = (1/3, 2/9)
The correct result would be <span>(1/3, 2/9)</span>.
For the first one, divide the figure into shapes you know how to use. This one can be turned into 2 rectangles and 1 square. Find the area (length*width) of each new shape and add them together. For example the rectangles would have an area that is 31*23 or 713 m.
For the second one do the same. It is 1 rectangle and 2 triangles. The area of a rectangle (length*width) in this case would be 24*8 or 192 cm and the area of the triangles are 1/2*base*height (you need to use the Pythagorean theorem to find the other length of the triangle) and add up the areas to get the total.
To find the surface area of the last one, there are 6 sides. The area of two of the sides are 15*4. Two of the sides are 15*3. The last two sides are 4*3. Add the areas up to find the total surface area.
Hope this helps! :)
